1. Field of the Invention
The present invention concerns a device for controlling the operating state of an automatic starting/stopping system for a thermal engine of a motor vehicle.
The invention finds a particularly advantageous application in the field of the automotive industry, and more especially in that of vehicles equipped with an automatic starting/stopping system, such as the system known by the English term “Stop and Go”.
2. Description of the Related Art
Vehicles able to function according to “Stop and Go” mode are equipped with a reversible electrical machine, or alternator/starter, coupled to the thermal engine, by means of a belt for example. In general terms, a reversible electrical machine of a vehicle combines two distinct functions, namely on the one hand the conventional function of alternator when the shaft of the thermal engine drives the rotor of the machine so as to produce an electric current at the stator and on the other hand the starter function when conversely a current applied to the stator of the machine causes the rotor to start to rotate, which then drives the shaft of the thermal engine in a similar manner to a conventional starter.
The application of an alternator/starter to the “Stop and Go” operating mode consists, under certain conditions, of causing the complete stoppage of the thermal engine when the vehicle is itself at rest, and then restarting the thermal engine following for example an action by the driver interpreted as a request for restarting. A typical situation with “Stop and Go” is that of stopping at a red light. When the vehicle stops at the light, the thermal engine is automatically stopped and then, when the light becomes green, the engine is restarted in particular by means of the alternator/starter following the detection by the vehicle starting control system of the pressing of the clutch pedal by the driver or any other action that may be interpreted as the intention of the driver to restart his vehicle. The advantage of the “Stop and Go” mode in terms of energy saving and pollution reduction, in particular in an urban environment, will be understood.
It is however necessary to emphasize that the functioning of such an automatic starting/stopping system is in general relatively complex because in particular of the implementation of many conditions that must be verified before any decision on automatic starting or stopping is taken, and because of the existence of intermediate operating modes, such as degraded modes, to which the system is subject under certain circumstances.
However, the decisions relating to automatic starting or stopping are by hypothesis made by the system unknown to the driver. The latter is therefore in total ignorance of the unfolding of the actions controlled by the automatic starting and stopping system concerning the functioning of the thermal engine of his vehicle, while, for reasons of safety and driving pleasure, he should be informed of this as precisely as possible.